


A Post-class Workout

by incredible_fish



Series: Byleth's extremely shameless smut situations [1]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Anal Sex, Deepthroating, Everyone is of consensual age, F/M, Femdom, Futa on Male, Futanari, Girl Penis, Mentions of Edelgard, Oral Sex, Pre-Timeskip | Academy Phase (Fire Emblem: Three Houses), Trans Female Character
Language: English
Status: Completed
Published: 2021-01-14
Updated: 2021-01-14
Packaged: 2021-03-18 12:48:20
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,972
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28743507
Author URL: https://archiveofourown.org/users/incredible_fish/pseuds/incredible_fish
Summary: Byleth enjoys one's student's company while contemplating her relationship with another.
Relationships: Linhardt von Hevring/My Unit | Byleth
Series: Byleth's extremely shameless smut situations [1]
Series URL: https://archiveofourown.org/series/2181915
Kudos: 19





	A Post-class Workout

**Author's Note:**

> Not enough big-dick muscle-mommy Byleth. Also I really like Linhardt.

It had been a long day of teaching and practical drills for Byleth and her students. The sun had already passed the horizon by the time they had finished, and as the Black Eagles dispersed from the dining hall the moon had taken its place in the sky. While Byleth certainly liked her class, she was also incredibly grateful that the teachers had their own bathing quarters separate from the students. It gave her a time and place to decompress from the day’s activity, the warm water soothing her strained muscles and the atmosphere switching her mind from battle-mode to relaxation-mode. Now thoroughly refreshed from the day’s happenings, Byleth made her way to her private quarters to finish up some documentation on her lessons.

On any other day, Byleth would have simply gone straight to bed after such an exhausting class. Today, however, was special. It was Wednesday, and Wednesday meant she was expecting somebody. Somebody who, as it so happened, had just knocked on Byleth’s door. It was a short, quiet knock, so quiet that only the persons on either side of the door could have heard it. The professor was quick to respond, rising from her chair and opening the door to greet the resident sleep expert of the Black Eagles. 

“Good evening, professor.” Linhardt greeted Byleth with his typical brand of nonchalance, though notability energetic given the time of day and his improvised nap schedule. “Might I come in? I’d like to... _talk_ , if it’s not a bother.” 

“Of course.” Byleth responded in her own minimalistic speech pattern, simply moving aside and gesturing for her student to enter. Closing and locking the door behind Linhardt, the professor spun to face her student. Demming it best to cut to the chase, Byleth wordlessly unbuckled her pants, letting them fall to the floor and stepped forward, her cock hanging freely between her legs. “Tell me what’s been bothering you.” A small smile crept onto Byleth’s lips, a smile Linhardt mirrored as he dropped to his knees.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It had been three months since Rhea had roped Byleth into this unorthodox teaching position. Three months out of her element, and three months the young mercenary had spent discovering that not only did she enjoy being a teacher, she also enjoyed the company of her students. Being of similar age to most of her students, if still older by a few years, it was easy to bond with them even in spite of Byleth’s lack of exposure to same-aged peers. This bond had worked wonders in strengthening the Black Eagle’s teamwork, every student in their house exceeding the academy’s expectations and garnering the praise of the rest of the faculty. 

Byleth would regularly meet with her class outside of lessons, both individually and as a whole, for no other reason than to enjoy their company. Such closeness meant that the bonds between student and teacher were strong for every member of the Black Eagles. So strong, in fact, that even somebody as emotionally absent as Byleth could tell when an individual as guarded as Edelgard had something bothering her. At first, the fledgling professor had tried approaching it directly, asking the emperor-to-be if there was anything on her mind, something she needed to share. These attempts were deflected with typical Adrestian grace; that is to say, Edelgard curtly stated that there was nothing to worry about and did her best to walk away from her professor as quickly as possible without actually running. 

After some sleuthing, Byleth had deduced two certain things: one, Edelgard’s sudden absent-mindedness meant that she had a crush. Two, and most important of all, that crush was directed towards none other than Byleth herself. Normally the stone-faced merc would never have even dreamed of the possibility of romantic feelings from the Adrestian heir, however, a few words with some overly-chatty female students and the discovery of numerous, discarded, half-finished portraits of the ashen-haired teacher meant it didn’t take a scholar to deduce what was now so blatantly obvious: Edelgard was a love-struck schoolgirl. 

Byleth had mixed feelings on this matter. On one hand, she definitely found Edelgard attractive and harbored similar feelings for her. On the other, Byleth had never considered the possibility of monganomy. Her time as a mercenary had meant a life of travel, and with travel came many new faces and very little stability when it came to relationships. It wasn’t uncommon for her comrades to share stories of their romps in the hay with the good townsfolk they’d met whilst moving from job to job, and moreover, it wasn’t unusual to find some mercs sharing a bunk for a night or two. Indeed, Byleth’s merry band of hired muscle were all very liberal in their relationships, and she in turn had picked up a similar view on love and sex. The two weren’t mutually exclusive, but neither did they have to be joined at the hip. This attitude had translated into a lot of one-night stands and casual sex friends for the daughter of Jeralt.

This, of course, also meant that Byleth found great difficulty in finding a solution to her and Edelgard’s problem. The professor knew that the longer she waited to express her feelings to the heir-apparent to the Adrestian Empire, the harder it would be to actually say anything. However, attempting to half-ass an exclusive relationship with her meant that neither would truly be happy and Byleth wouldn’t dare break El’s heart like that. 

To make matters worse, Byleth was also _extremely horny_. Since joining Garrech Mach Monastery, she’d had little time to herself, let alone enough time to find so much as a prostitute to relieve herself upon. Her libido had always been rather troublesome, though the mercenary life made it manageable, as there were partners aplenty for a big, strong mercenary looking to relax after protecting the good townsfolk. As a teacher, however, there were very different expectations, and Byleth figured it would probably reflect badly not only on the school, but on her students if she had careless hook-ups every other moon. This pent-up arousal clouded Byleth’s judgement just a tad, enough to make her make mistakes. 

Indeed, even with the power of a creator god on her side, Byleth was still vulnerable. Tight pants make a terrible partner to a typically level-headed mercenary, and in battle they could spell doom for the distracted party. The Black Eagles had been deployed to help fend off a particularly persistent group of bandits that they’d clashed with previously, this time harassing a small settlement just off the road to the Monastery. These bandits were an aggressive bunch, not afraid of getting messy with their enemies. The Black Eagle class came prepared and made short work of the uncoordinated bunch of miscreants, but not before they launched one final assault with their remaining numbers. While the rest of the class had pushed forward, the western flank of the town had been left guarded by Edelgard, Byleth, Hubert, and Linhardt. A small group compared to the rest of the class, the bandits decided that they were suitable enough for attack. On any other occasion they would’ve been dead wrong, but two of this defensive flank were both hopelessly distracted by one another, and even as the last of the bandits fell, Byleth had stepped in to protect her beloved student from a blow either of them should have seen coming from miles away. 

It was not a fatal blow, thus neither Byleth nor Sothis saw the need for a temporal do-over, though it was on that required treatment nonetheless. It was lucky, then, that both Hubert and Linhardt were close and ready to assist; Hubert to draw a blubbering Edelgard away and preserve her image as the pinnacle of a level-headed warrior-emperor, and Linhardt to actually treat their wounded professor. 

With the bandit threat dealt with, the young healer was able to take his time and do a proper job of sealing the nasty gash Byleth had received across her arm. However, no longer distracted by the heat of battle, and in such close proximity to a specimen as attractive as the effeminate Linhardt, Byleth’s arousal quickly made itself known to both its owner and the up and coming crest scholar. A number of things ran through Linhardt’s mind in this instant; first off, there was a sizable erection tenting the pants of his patient. Secondly, that patient was his own professor. Thirdly, Linhardt’s own erection had sprung up in response to this sight. Finally, the two were completely alone in this healer’s tent and were likely to remain undisturbed for a long while due to the sensitive nature of the environment. Teacher and student locked eyes, both clearly unsure of how to proceed. After what seemed like an eternity in silence, Byleth’s lust pushed her to make the first move. 

“Linhardt.” Her voice was husky and punctuated, “If it’s alright, I believe I require a _thorough_ examination.” A sultry expression formed on the woman’s face, her lower garments practically creaking as her length stiffened further with the word _thorough_. 

The healer’s lips curved ever so slightly upwards as Byleth’s words reached his ears. Responding with his own cheeky innuendo, Linhardt moved his hand to rest on his teacher’s thigh. “Of course, professor. In fact, I was hoping to use this time to practice my _bedside manner_.”

A day later and the Black Eagles were back at Garreg Mach. A day after that, Edelgard had delivered a short and awkward apology to her teacher, citing the incident as her fault alone and promising it wouldn’t happen again. By this time, Linhardt and Byleth had also met privately once more and had discussed Byleth’s position in depth. Their friendship blossomed further than before, and Byleth was both happy to have deepened her relationship with her student, and relieved to have found a receptacle for her lust. 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

One month after the bandit scuffle and there Byleth stood, bare-fleshed, her student worshipping her throbbing tool with hand and mouth. Linhardt hat began by littering the turgid member with little pecks, coaxing her to a full 15 inches before moving on to massage Byleth’s swollen cum sack with his tongue. Byleth let out a deep hum of approval, the sound like music to Linhardt’s ears. He responded by taking it a step further, releasing his mouth’s grasp on her testes and moving towards her cockhead. Warm exhales tickled Byleth’s breeding organ, causing it to twitch and flick her student’s nose. Linhardt was just as eager, crossing his arms behind his back and opening his mouth wide, plush lips inviting his teacher inside. 

“Don’t mind if I do.” Byleth stepped forward, inserting her tip and inching her way into those wonderfully welcoming depths. It wasn’t long before Linhardt was french kissing the professor’s crotch, his nose planted firmly on Byleth’s waist and neck bulged with her arousal. Linhardt’s head was empty now, save for the smell of his professor’s bitch breaker. Luckily he didn’t need to think right now, as his dutiful teacher was more than content to grab his head and use him like the cocksleeve he so enjoyed acting like. 

At first Byleth was content sliding her student’s face up and down her length lazily, simply taking in the sight of his lips wrapped around her cock. In turn, the sight of his chiseled teacher taking control from between her powerful thighs sent a whirlwind of satisfaction through Linhardt. Soon, though, her approach changed, and Byleth held his head in place and all but rammed herself back down Linhardt’s throat. 

“Glk!” The noise Linhardt made was involuntary, a byproduct of the sudden strategy change by Byleth forcing the air and spit out from what few gaps remained between his lips and her dick. Perturbed, however, he was not, as his viewpoint had only improved; Byleth had taken to removing what few clothes she still had left to discard, all but ripping off her shirt and exposing her plump tits, the only thing on her body that could be described with the word “soft.” It overjoyed Linhardt to see his teacher in her full splendor, her powerful, muscular frame and gripping his head while that pillowy chest bounced in response to her savage thrusts. Combined with the rigid rod wrecking his throat and the fact that he didn’t even have to lift a finger for such a wonderful time, Linhardt found himself contemplating the meaning of the word “Heaven.”

Byleth too pondered something, a subject which roused a certain green-haired passenger from her slumber deep in the professor’s head. “My, you certainly aren’t holding back tonight. Got a few frustrations to work out?” Sothis appeared and floated just behind Byleth, leaning over her shoulder to get a good look at the action. The teacher paid the gremlin goddess no mind, yet she continued regardless. “You know, it’s rather difficult to get a decent sleep in while it’s so busy in that cluttered little head of yours. Difficult indeed, when images of a certain Adrestian Heir dance day and night…” 

Byleth shot her spectral companion a sideways glance, never once halting or changing the pace of her thrusts all the while. A small frown accompanied furrowed brow, and the message was read loud and clear. “I’m just saying, you two really ought to just sit down and talk about this. You’re making it out to be far more complicated than it actually is.” Sothis hovered closer. “I’m sure that even this little…” she glanced down again at the young scholar gagging beneath her host, “let’s call it an arrangement, would go overlooked or even understood if you just talked to Edelgard as equals. If your love is true, I’m even certain that she wouldn’t mind sharing….” She trailed off, but the implied tone of experience wasn’t lost on Byleth. The teacher huffed in response, a sound only audible to her and the incorporeal being. “Fine. I’ve said my piece, so I’ll let you get back to it. So long as you’ve considered my words, I should have little trouble getting a good night’s sleep.” Sothis let out a long yawn, stretching her arms as she slowly faded from Byleth’s vision. Suddenly there were once again only two left in the room, and Byleth became acutely aware of a familiar tightness surging up from her aching balls. 

She slowed for only a second, long enough to let one hand leave her student’s face and slapped him, rousing Linhardt from his blissed-addled coma and drawing his attention back to her. They locked eyes, and after a feeling the massive bitch breaking throb in his throat, Linhardt knew what time it was. Byleth pulled back and out of the scholarly student’s mouth, bringing one hand to her shaft and pumping it with the same vigor she’d put into filling Linhardt’s throat not moments before. For his part, Linhardt remained perfectly still, positioning his hands just under his still gaping mouth and the throbbing member an inch from his face. A moment longer and Byleth let out a deep groan.

“Ooohhh…. Fuck….” One final pump and the blue-haired woman threw her head back, spewing her load all over her diligent cock-sucker. The first jet caused her member to jerk upwards, landing in Lin’s mouth whilst also painting his face from chin to hair. The next shots weren’t as violent, most of their payload striking home across the young man’s patient tongue. Linhardt shivered in delight with each rope, delighting in the salty spunk drowning his taste buds. Soon Byleth pushed forward once more, forcing her tip back into that slick hole, resting her still spurting tip just past his lips. Together they rode out the remainder of her orgasm, Byleth once again removing her cock to gaze upon her handiwork. Their post-nut ritual commenced, and the mercenary held Linhardt by the chin and lifted his face to hers. Her tool throbbed at the sight in spite of the recent orgasm.

Her student’s face was delightfully disheveled, tears running down his cheeks, though they were clearly instinctual, byproducts of Byleth’s rough treatment. Cum matted the hair that hung now unbound over his face, his hair tie having been removed some time ago. More semen still caked the space between the top of his head all the way to his chin, with a ring of spit and spunk acting as lipstick for the cum-drunk scholar. Lin’s mouth still hung open, a reservoir of baby batter displayed for his teacher. His entire visage was like a monument to Byleth’s impressive virility, and for such a picture-perfect performance he deserved a reward.  
  


With only a ghost of a smirk, Byleth uttered a single word. “Swallow.” Linhardt obeyed, gulping down her creamy load and licking his lips clean afterward. He opened his mouth once more to show he was finished. Methodically, Byleth traced her thumb across Linhardt’s face, catching the remainder of her load and escorting it back towards his orifice until her greedy cum-guzzler was relatively clean. With the last pass she let her thumb linger in Lin’s mouth, the young man meeting it with his tongue and suckling it with reverence. Byleth felt her loins trembling once more, and soon after she decided what was next. Linhardt was saddened to feel his mistress’s hands leave his face, but disappointment quickly transformed to joy when Byleth motioned to the bed.

“I know how much you love sleeping, how about you show me your favorite position?” Keeping in line with their earlier innuendos, the professor knew Linhardt would want to steer things in such a way where he would exert minimal effort. As predicted, the younger male grasped the opportunity and scurried onto the bed while Byleth grabbed a bottle of lubricant and slathered a liberal amount over her tool. He laid with his frontside towards the professor’s bedding, turning his head just enough to see behind and reaching his hands to spread his ass. The entire scene tickled Byleth’s primal urges and the teacher climbed on the bed with a predatory gaze. Allowing herself a moment to admire the pillow-like behind presently presenting itself, she drew her tongue across one cheek and gave the other a hard smack before aligning her cockhead with his pucker, stealing a final glance at Linhardt’s face to drink in the anticipation currently masking it. For Lin, the last thing he saw was the professor’s confident smirk, dripping with hunger. After that, only stars. 

With hands firmly planted on his pliable tush, one thrust was all it took to bottom out. A resounding _smack_ marked the occasion, Byleth’s obscenely large sack engulfing her student’s forgotten manhood below. With her feet firmly planted on either side of Linhardt’s tush, she began her assault immediately. With every blow the scholar could feel his stomach bulging, his insides nearly rearranging themselves to accommodate the mercenary’s shaft. 

The fledgling scholar beneath Byleth went slack, his arms limp at his sides, content to enjoy the ride and leave the heavy lifting to his dear professor. Her position made it hard to do much else, anyways; the herculean thrusts into his soft behind knocking any ideas of Linhardt’s input out of his mind and body. He was merely a warm hole for his teacher to relieve her arousal with, the only noises uttered from the student being instinctual moans or grunts from whenever Byleth hilted herself just right. 

For her part, the experienced merc’s guttural growls were the only thing louder than the clapping of flesh, Byleth’s brain now focused solely on the prospect of planting her seed deep in the fields her tool worked to plow. Now slick with sweat, Byleth felt her grip on her onahole’s hip slipping, and so let go, only to find a new anchor point on Linhardt’s arms. The professor pulled back on his limbs like reigns, quite literally riding the boy’s ass. Both parties found this arrangement incredibly pleasurable, and it didn’t take much longer for teacher and student to feel a familiar twitch in their groins. 

One thrust directly on the ravaged scholar’s prostate was all it took after that familiar signal of impending orgasm, his neglected tool pitifully spurting its useless payload onto the sheets behind him. His whole body grew tense in response, his quivering boy pusssy most of all. This in turn sent Byleth over the edge as well, ending her attack with one final sheathing thrust. Now balls-deep again, Linhardt felt his stomach bulge with more than just that massive breeder’s stick. The professor’s sloshing sack trembled as it shot thick ropes of her essence into the abused rectum, Byleth’s cumslit disdending almost painfully to accommodate such a voluminous load. Her unmatched virility once again on display, the vacuum-tight seal around her cock was broken by her own excess. A river of ivory leaked out from around the mercenary’s dick, and for a time it seemed as though the tide would never end. 

Soon, however, the floodgates closed, and both seeder and seeded were left panting, both keenly aware of the other’s heart rate through the bridge between their crotches. Byleth released her iron grip on Lin’s arms, letting him flop unceremoniously onto the pillow below. She slowly removed her now spent tool, basking in the sensation of suction that the exchange provided. The professor took a second to take in the well-gaped hole before her, littered with the evidence of her deposit. Humming a nondescript tune to herself, Byleth painted the boy’s bottom with the remainder of her spunk and reached over to her night stand to pull out something to alleviate any further mess. Buttplug in hand, she stuffed the now empty hole to keep her load snug in her student’s depths, the young man letting out a small yet appreciative moan in response. 

There was just enough room on the bed for Byleth to lay down next to Linhardt, crossing her arms behind her head as she stared at the ceiling to enjoy the afterglow. Linhardt, in turn, realized his favorite pillows had made an appearance, and used what little strength he had left to turn and wrap one arm around his teacher’s abbs, a leg around her own, and planted his cheek parallel to Byleth’s breasts. The two enjoyed each other’s warmth, though with the sudden lull to activity came the resurgence of the merc’s earlier ponderings. She let out a sigh through her nose as thoughts of Edelgard pranced through her head, no doubt irritating her non-corporeal passenger to no end. Her corporeal companion also took note, quickly picking up on the fact that her exhilation was not one of post-coital relief. 

“Thinking about our dear prim princess again?” Linhardt’s intuition proved correct, and Byleth simply sighed once again. “I might not be the most adept at social cues, but if you two really do hold the same feelings for one another, don’t you think she’d understand your tendency to _sleep around_?” 

Byleth stole a glance down at weight on her chest, and her eyes met Linhardt’s. She knew he was right, and so was Sothis. She loved Edelgard, and she also loved having sex, and if the Adrestian heir felt anywhere near how the professor felt, then she’d understand Byleth’s preference to hold multiple partners. The teacher let out a hum of agreeance, now busy focusing her thoughts as to when she should confess to the object of her affections. 

“That wasn’t so hard right? Just tell her tomorrow after dinner or class.” With that, Linhardt was content that the matter was resolved, and closed his eyes so as to drift off to sleep. Byleth followed suit, a grin forming on her lips at the thought of finally telling her white-haired friend just how much she meant to the mercenary. 

**Author's Note:**

> Might do a follow-up/sequel with Edelgard someday. Not anytime soon tho, so don't get too excited. Hope you enjoyed!


End file.
